Hayley Brennan, Chloe Brennan, Melanie Plant, and Sonja Brennan, with the updated Book of Life, open at the page of their story, at the Launch of Donate Life Week.

Hayley Brennan, Chloe Brennan, Melanie Plant, and Sonja Brennan, with the updated Book of Life, open at the page of their story, at the Launch of Donate Life Week. Photo: Rohan Thomson

As a way of honouring him, the four most important women in Mitchell Brennan's life had his name tattooed on their limbs.

His mother and three sisters made the difficult decision to donate the 18-year-old's organs after a car accident left him brain dead.

But at the launch of DonateLife Week yesterday, his sister Melanie Plant said the decision would have been much easier if they had known Mitchell's wishes.

''We made our decision that day based on our belief of what Mitch would have wanted.

''However, it would have been made so much easier if we had known his wishes,'' Mrs Plant said.

The young Victorian, who dreamed of being a paramedic, hit a tree while travelling at 55km/h just 44 days after gaining his driver's licence.

''Nothing was going to change our situation, but if we could save one family from the grief we were feeling it was worth doing,'' she said.

About 1600 people are on Australian organ transplant waiting lists. Each year about 20 per cent of those waiting for heart, lung, kidney or liver transplants die before they receive them. Last year, 337 organ donors gave 1001 Australians a new life. And while Australia's donation rate has increased by 4.7 donors per million people to 14.9 donors per million people in the past two years, consent is still an issue. Of the 730 potential donors last year, only 390 families consented.

This year the Organ and Tissue Authority is hoping more young adults will discuss organ donation with their families.

DonateLife Ambassador Governor-General Quentin Bryce urged young Australians - who are less likely to have discussed or made a decision about organ donation - to talk with their families.

For Mitchell's sisters, knowing other families have been saved the grief of losing a loved one gives them comfort.

''Mitchell only died 14 months ago, and you never get over the loss.

''But for us it gives some comfort to know that we have helped other families, and that they don't have to suffer the way we are suffering,'' Mrs Plant said.

''Mitchell saved a young girl. It's not about keeping Mitchell's memory alive, we'll always remember him.

''It's about saving others from what we're going through.''

DonateLife Week starts February 19. For more information visit www.donatelife.gov.au